/*
    * The SmartWeb Framework
    * Copyright (C) 2004-2006
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
    *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   *
   * For further informations on the SmartWeb Framework please visit
   *
   *                        http://smartweb.sourceforge.net
   */
  package net.smartlab.web;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import net.smartlab.web.DataAccessObject.SearchInfo.Filter;
  import net.smartlab.web.bean.ConversionException;
  import net.smartlab.web.bean.ConverterManager;
  import net.smartlab.web.config.FactoryConfigurationStrategy;
  import net.smartlab.web.config.JNDIConfigurationStrategy;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.hibernate.Criteria;
  import org.hibernate.FetchMode;
  import org.hibernate.HibernateException;
  import org.hibernate.Query;
  import org.hibernate.Session;
  import org.hibernate.SessionFactory;
  import org.hibernate.Transaction;
  import org.hibernate.criterion.Expression;
  import org.hibernate.criterion.Order;
  import org.hibernate.criterion.Projections;
  import org.hibernate.impl.CriteriaImpl;
  import org.hibernate.impl.SessionImpl;
  import org.hibernate.metadata.ClassMetadata;
  import org.hibernate.persister.entity.EntityPersister;
  import org.hibernate.transform.ResultTransformer;
  
  /**
   * This class provides basic template for an Hibernate based implementation of
   * the DAO pattern.
   * 
   * @author rlogiacco,gperrone
   * @uml.dependency supplier="net.smartlab.web.DataTransferObject"
   * @uml.dependency 
   *                 supplier="net.smartlab.web.config.FactoryConfigurationStrategy"
   */
  public abstract class BusinessObjectFactory implements DataAccessObject {
  
  	/**
  	 * Provides logging capabilities to the factory.
  	 */
  	protected final Log logger = LogFactory.getLog(this.getClass());
  
  	/**
  	 * Stores the Hibernate Session instance available for this request.
  	 */
  	private static final ThreadLocal sessions = new ThreadLocal();
  
  	/**
  	 * Stores the Hibernate Transaction instance available for this request.
  	 */
  	private static final ThreadLocal transaction = new ThreadLocal();
  
  	/**
  	 * Caches a reference to the Hibernate Session Factory to avoid further
  	 * lookups.
  	 */
  	protected SessionFactory factory;
  
  	/**
  	 * Strategy to retrieve the configuration file.
  	 */
  	private static FactoryConfigurationStrategy strategy = new JNDIConfigurationStrategy();
  	static {
  		try {
  			String strategy = System.getProperty("smartweb.factory.strategy");
  			if (strategy != null) {
 				BusinessObjectFactory.strategy = (FactoryConfigurationStrategy)Class.forName(strategy).newInstance();
 			} else {
 				LogFactory.getLog(BusinessObjectFactory.class).warn(
 						"No configuration found: falling back to default configuration");
 			}
 		} catch (Exception e) {
 			LogFactory.getLog(BusinessObjectFactory.class).fatal("Error configuring SmartWeb", e);
 		}
 	}
 
 
 	/**
 	 * Changes the strategy used to configure the framework.
 	 * 
 	 * @param strategy an implementation of the
 	 *        <code>FactoryConfigurationStrategy</code> interface.
 	 */
 	public static void setConfigurationStrategy(FactoryConfigurationStrategy strategy) {
 		BusinessObjectFactory.strategy = strategy;
 	}
 
 	/**
 	 * Closes the connection to the persistence tier.
 	 * 
 	 * @throws DAOException if the persistence tier generates any error while
 	 *         performing the resource release.
 	 */
 	public static void close() throws DAOException {
 		Map sessions = (Map)BusinessObjectFactory.sessions.get();
 		if (sessions != null) {
 			Iterator iterator = sessions.values().iterator();
 			while (iterator.hasNext()) {
 				Session session = (Session)iterator.next();
 				if (session != null && session.isOpen()) {
 					try {
 						session.flush();
 						session.close();
 					} catch (HibernateException he) {
 						throw new DAOException("session.error.close", he);
 					} finally {
 						BusinessObjectFactory.sessions.set(null);
 					}
 				}
 			}
 		}
 	}
 
 	/**
 	 * @TODO documentation
 	 * @throws DAOException
 	 */
 	public static void flush() throws DAOException {
 		Map sessions = (Map)BusinessObjectFactory.sessions.get();
 		if (sessions != null) {
 			Iterator iterator = sessions.keySet().iterator();
 			while (iterator.hasNext()) {
 				Session session = (Session)sessions.get(iterator.next());
 				if (session != null && session.isOpen()) {
 					try {
 						session.flush();
 					} catch (HibernateException he) {
 						throw new DAOException("session.error.close", he);
 					} finally {
 						BusinessObjectFactory.sessions.set(null);
 					}
 				}
 			}
 		}
 	}
 
 	/**
 	 * Protected default constructor to allow subclassing. Provides the startup
 	 * initialization and the Hibernate Session Factory lookup. The Hibernate
 	 * configuration file used must reside into the <code>META-INF</code>
 	 * directory of the topmost packaging archive and should be named
 	 * <code>smartweb.jar.hcf</code> or have the name of the JAR file containing
 	 * the subclass followed by the <code>.hcf</code> suffix. TODO example
 	 */
 	protected BusinessObjectFactory() {
 		this.factory = strategy.getSessionFactory(this);
 	}
 
 	/**
 	 * Returns the current Hibernate Session. If a Session was previously
 	 * established during the same request the already established instance is
 	 * returned otherwise a new instance is retrieved from the Session Factory.
 	 * 
 	 * @return the current connection to the persistence layer or a new one if
 	 *         not previously established.
 	 * @throws DAOException if an error occurs trying to establish the
 	 *         connection.
 	 */
 	protected Session current() throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("current() - start");
 		}
 		Map sessions = (Map)BusinessObjectFactory.sessions.get();
 		if (sessions == null) {
 			sessions = new HashMap();
 			BusinessObjectFactory.sessions.set(sessions);
 		}
 		try {
 			Session session = (Session)sessions.get(factory);
 			if (session == null) {
 				try {
 					session = factory.openSession();
 					sessions.put(factory, session);
 				} catch (Exception e) {
 					throw new DAOException("session.error.config", e);
 				}
 			}
 			return session;
 		} catch (Exception e) {
 			throw new DAOException("session.error.config.not-found", e);
 		}
 	}
 
 	/**
 	 * @see net.smartlab.web.DataAccessObject#findByKey(java.io.Serializable)
 	 */
 	public Object findByKey(Serializable key) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("findByKey(key = " + key + ") - start");
 		}
 		Serializable convertedKey = this.convertKey(key);
 		if (convertedKey == null) {
 			try {
 				logger.debug("findByKey(key = " + key + ") - new instance");
 				return this.getMappedClass().newInstance();
 			} catch (Exception e) {
 				logger.debug("findByKey(key = " + key + ") - instantiation failed", e);
 				throw new DAOException("session.error.select", e);
 			}
 		} else {
 			Session session = this.current();
 			try {
 				return session.get(this.getMappedClass(), convertedKey);
 			} catch (HibernateException he) {
 				logger.debug("findByKey(key = " + key + ") - deserialization failed", he);
 				throw new UndefinedKeyException(key, this.getMappedClass(), he);
 			}
 		}
 	}
 
 	/**
 	 * @TODO documentation
 	 * @param key
 	 * @param fetch
 	 * @return
 	 * @throws DAOException
 	 */
 	public Object findByKey(Serializable key, String[] fetch) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("findByKey(key = " + key + ", fetch = " + fetch + ") - start");
 		}
 		Serializable convertedKey = this.convertKey(key);
 		if (convertedKey == null) {
 			try {
 				return this.getMappedClass().newInstance();
 			} catch (Exception e) {
 				logger.debug("findByKey(key = " + key + ") - instantiation failed", e);
 				throw new DAOException("session.error.select", e);
 			}
 		} else {
 			Session session = this.current();
 			try {
 				EntityPersister persister = ((SessionImpl)session).getFactory().getEntityPersister(
 						this.getMappedClass().getName());
 				Criteria criteria = session.createCriteria(this.getMappedClass());
 				criteria.add(Expression.eq(persister.getIdentifierPropertyName(), convertedKey));
 				if (fetch != null) {
 					for (int i = 0; i < fetch.length; i++) {
 						criteria.setFetchMode(fetch[i], FetchMode.JOIN);
 					}
 				}
 				return criteria.uniqueResult();
 			} catch (HibernateException he) {
 				logger.debug("findByKey(key = " + key + ", fetch = " + fetch + ") - deserialization failed", he);
 				throw new UndefinedKeyException(key, this.getMappedClass(), he);
 			}
 		}
 	}
 
 	/**
 	 * @see net.smartlab.web.DataAccessObject#remove(java.lang.Object)
 	 */
 	public void remove(Object object) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("remove(object = " + object + ") - start");
 		}
 		try {
 			this.current().delete(object);
 		} catch (HibernateException he) {
 			logger.debug("remove(object = " + object + ") - failed", he);
 			throw new DAOException("session.error.remove", he);
 		}
 	}
 
 	/**
 	 * @see net.smartlab.web.DataAccessObject#update(java.lang.Object)
 	 */
 	public void update(Object object) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("update(object = " + object + ") - start");
 		}
 		try {
 			this.current().saveOrUpdate(object);
 		} catch (HibernateException he) {
 			logger.debug("update(object = " + object + ") - failed", he);
 			this.current().clear();
 			throw new DAOException("session.error.update", he);
 		}
 	}
 
 	/**
 	 * @see net.smartlab.web.DataAccessObject#list(net.smartlab.web.DataAccessObject.SearchInfo)
 	 */
 	public Collection list(SearchInfo info) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("list(info = " + info + ") - start");
 		}
 		Criteria criteria = this.createCriteria(info);
 		try {
 			return criteria.list();
 		} catch (HibernateException he) {
 			logger.debug("list(info = " + info + ") - failed", he);
 			throw new DAOException("session.error.search", he);
 		}
 	}
 
 	/**
 	 * @TODO documentation
 	 * @param info
 	 * @param fetch
 	 * @return
 	 * @throws DAOException
 	 */
 	public Collection list(SearchInfo info, String[] fetch) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("list(info = " + info + ", fetch = " + fetch + ") - start");
 		}
 		try {
 			Criteria criteria = this.createCriteria(info);
 			for (int i = 0; i < fetch.length; i++) {
 				criteria.setFetchMode(fetch[i], FetchMode.SELECT);
 			}
 			return criteria.list();
 		} catch (HibernateException he) {
 			logger.debug("list(info = " + info + ", fetch = " + fetch + ") - deserialization failed", he);
 			throw new DAOException("session.error.search", he);
 		}
 	}
 
 	/**
 	 * Returns a collection of objects representing all the persistence tier
 	 * informations matching the specified set of unique identification keys and
 	 * search criterias.
 	 * 
 	 * @param keys the set of keys to be matched.
 	 * @param info the additional criterias to be used to search the persistence
 	 *        tier.
 	 * @return a collection of matching entities.
 	 * @throws DAOException if an error occur while accessing the persistence
 	 *         tier
 	 */
 	public Collection listByKeySet(Set keys, SearchInfo info) throws DAOException {
 		return this.listByKeySet(keys, info, false);
 	}
 	
 	/**
 	 * Returns a collection of objects representing all the persistence tier
 	 * informations matching the specified set of unique identification keys and
 	 * search criterias.
 	 * 
 	 * @param keyFieldName the fieldName to be matched for unique identification
 	 *        key.
 	 * @param keys the set of keys to be matched.
 	 * @param info the additional criterias to be used to search the persistence
 	 *        tier.
 	 * @return a collection of matching entities.
 	 * @throws DAOException if an error occur while accessing the persistence
 	 *         tier
 	 * @deprecated the keyFieldName parameter is no more needed
 	 * @see #listByKeySet(java.util.Set, net.smartlab.web.DataAccessObject.SearchInfo, boolean)
 	 */
 	public Collection listByKeySet(String keyFieldName, Set keys, SearchInfo info) throws DAOException {
 		return this.listByKeySet(keys, info, false);
 	}
 
 	/**
 	 * Returns a collection of objects representing all the persistence tier
 	 * informations matching the specified set of unique identification keys and
 	 * search criterias.
 	 * 
 	 * @param keys the set of keys to be matched.
 	 * @param info the additional criterias to be used to search the persistence
 	 *        tier.
 	 * 
 	 * @param exclude if the keys should be included or excluded from the list.
 	 * @return a collection of matching entities.
 	 * @throws DAOException if an error occur while accessing the persistence
 	 *         tier
 	 */
 	public Collection listByKeySet(Set keys, SearchInfo info, boolean exclude) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("list(keys = " + keys + ", info = " + info + ", exclude = " + exclude + ") - start");
 		}
 		Criteria criteria = this.createCriteria(info);
 		String identifier = 
 			factory.getClassMetadata(this.getMappedClass()).getIdentifierPropertyName();
 		keys = this.convertKeys(keys);
 		if (identifier != null && !keys.isEmpty()) {
 			if (exclude) {
 				criteria.add(Expression.not(Expression.in(identifier, keys)));
 			} else {
 				criteria.add(Expression.in(identifier, keys));
 			}
 		}
 		try {
 			return criteria.list();
 		} catch (HibernateException he) {
 			throw new DAOException("session.error.search", he);
 		}
 	}
 
 	/**
 	 * Returns a paginable collection of objects representing all the
 	 * persistence tier informations matching the specified search criterias.
 	 * 
 	 * @param info the criterias to be used filter the instances.
 	 * @return a paginable collection of objects matching the specified search
 	 *         criterias.
 	 * @throws DAOException if an error occur while accessing the persistence
 	 *         tier
 	 */
 	public Collection page(SearchInfo info) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("page(info = " + info + ") - start");
 		}
 		Criteria criteria = this.createCriteria(info);
 		try {
 			return new Paginator(criteria);
 		} catch (HibernateException he) {
 			logger.debug("page(info = " + info + ") - error", he);
 			throw new DAOException("session.error.paging", he);
 		}
 	}
 
 	/**
 	 * @TODO documentation
 	 * @param info
 	 * @param fetch
 	 * @return
 	 * @throws DAOException
 	 */
 	public Collection page(SearchInfo info, String[] fetch) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("page(info = " + info + ", fetch = " + fetch + ") - start");
 		}
 		try {
 			Criteria criteria = this.createCriteria(info);
 			for (int i = 0; i < fetch.length; i++) {
 				criteria.setFetchMode(fetch[i], FetchMode.SELECT);
 			}
 			return new Paginator(criteria);
 		} catch (HibernateException he) {
 			logger.debug("page(info = " + info + ", fetch = " + fetch + ") - deserialization failed", he);
 			throw new DAOException("session.error.paging", he);
 		}
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @return
 	 */
 	public abstract Class getMappedClass();
 
 	/**
 	 * Converts a generic serializable object to the type used as unique key
 	 * identifier for this type of BusinessObject. The default implementation
 	 * converts String or Number to Long using the <code>o</code> value to
 	 * identify non-persisted instances. If your business definition requires a
 	 * different conversion you should override this method to provide your own
 	 * conversion strategy.
 	 * 
 	 * @param key the generic serializable key that needs to be converted.
 	 * @return the key representation using the correct type or
 	 *         <code>null</code> if the providen key doesn't represent a valid
 	 *         identifier for a persisted BusinessObject.
 	 */
 	public Serializable convertKey(Serializable key) {
 		if (key != null) {
 			if (key instanceof String) {
 				key = ((String)key).trim();
 				if (((String)key).length() == 0 || key.equals("0")) {
 					return null;
 				} else {
 					return new Long((String)key);
 				}
 			} else if (key instanceof Number) {
 				if (((Number)key).longValue() == 0) {
 					return null;
 				} else {
 					return new Long(((Number)key).toString());
 				}
 			}
 		}
 		return key;
 	}
 
 	/**
 	 * Converts a generic set of serializable objects to a set containing
 	 * objects of the type used as unique key identifier for this type of
 	 * BusinessObject using the <code>convertKey()</code> method.
 	 * 
 	 * @param keys the <code>java.util.Set</code> of serializable objects to be
 	 *        converted.
 	 * @return a <code>java.util.Set</code> containing appropriately converted
 	 *         keys.
 	 */
 	public Set convertKeys(Collection keys) {
 		if (keys == null) {
 			return Collections.EMPTY_SET;
 		}
 		Set converted = new HashSet(keys.size());
 		Iterator iterator = keys.iterator();
 		while (iterator.hasNext()) {
 			converted.add(this.convertKey((Serializable)iterator.next()));
 		}
 		return converted;
 	}
 
 	/**
 	 * Creates an Hibernate <code>Criteria</code> instance using filtering and
 	 * ordering rules defined through the <code>SearchInfo</code> structure.
 	 * 
 	 * @param info
 	 * @return
 	 * @throws DAOException
 	 */
 	public Criteria createCriteria(SearchInfo info) throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("createCriteria(info = " + info + ") - start");
 		}
 		Session session = this.current();
 		Criteria criteria = session.createCriteria(this.getMappedClass());
 		if (info != null) {
 			ClassMetadata metadata = session.getSessionFactory().getClassMetadata(this.getMappedClass());
 			ConverterManager converter = ConverterManager.getDefault();
 			if (info.isUnion()) {
 				// TODO the filters are in OR
 			}
 			Iterator filters = info.getFilters().iterator();
 			while (filters.hasNext()) {
 				Filter filter = (Filter)filters.next();
 				if (logger.isTraceEnabled()) {
 					logger.trace("createCriteria(info = " + info + ") - parsing filter `" + filter + "`");
 				}
 				Class type = metadata.getPropertyType(filter.getProperty()).getReturnedClass();
 				try {
 					switch (filter.getCondition()) {
 						case SearchInfo.EQUALS:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.eq(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.GREATER:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.gt(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.GREATER_EQUALS:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.ge(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.LESSER:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.lt(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.LESSER_EQUALS:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.le(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.NOT_EQUALS:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.ne(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.BETWEEN:
 							Object start = converter.convert(type, filter.getValue(0), info.getLocale());
 							Object stop = converter.convert(type, filter.getValue(1), info.getLocale());
 							criteria.add(Expression.between(filter.getProperty(), start, stop));
 							break;
 						case SearchInfo.IN: {
 							Collection values = new ArrayList();
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i),
 										info.getLocale());
 								if (value != null) {
 									values.add(value);
 								}
 							}
 							if (!values.isEmpty()) {
 								criteria.add(Expression.in(filter.getProperty(), values));
 							}
 							break;
 						}
 						case SearchInfo.NOT_IN: {
 							Collection values = new ArrayList();
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i),
 										info.getLocale());
 								if (value != null) {
 									values.add(value);
 								}
 							}
 							if (!values.isEmpty()) {
 								criteria.add(Expression.not(Expression.in(filter.getProperty(), values)));
 							}
 							break;
 						}
 						case SearchInfo.LIKE:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.like(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.ILIKE:
 							for (int i = 0; i < filter.getValues().length; i++) {
 								Object value = converter.convert(type, filter.getValue(i), info.getLocale());
 								criteria.add(Expression.ilike(filter.getProperty(), value));
 							}
 							break;
 						case SearchInfo.NULL:
 							criteria.add(Expression.isNull(filter.getProperty()));
 							break;
 						case SearchInfo.NOT_NULL:
 							criteria.add(Expression.isNotNull(filter.getProperty()));
 							break;
 					}
 				} catch (ConversionException ce) {
 					logger.warn("Unable to convert filter `" + filter + "`", ce);
 				}
 			}
 			if (info.getOrder() != null && info.getOrder().length() > 0) {
 				if (info.isDescendant()) {
 					criteria.addOrder(Order.desc(info.getOrder()));
 				} else {
 					criteria.addOrder(Order.asc(info.getOrder()));
 				}
 			}
 		}
 		return criteria;
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @throws DAOException
 	 */
 	public void begin() throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("begin() - start");
 		}
 		if (BusinessObjectFactory.transaction.get() == null) {
 			try {
 				BusinessObjectFactory.transaction.set(this.current().beginTransaction());
 			} catch (HibernateException he) {
 				logger.debug("begin() - error", he);
 				throw new DAOException("session.error.begin", he);
 			}
 		} else {
 			logger.warn("begin() - transaction already started");
 		}
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @throws DAOException
 	 */
 	public void commit() throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("commit() - start");
 		}
 		Transaction transaction = (Transaction)BusinessObjectFactory.transaction.get();
 		try {
 			transaction.commit();
 		} catch (HibernateException he) {
 			logger.debug("commit() - error", he);
 			throw new DAOException("session.error.commit", he);
 		} catch (NullPointerException npe) {
 			logger.debug("commit() - transaction never started");
 			throw new DAOException("session.error.commit");
 		} finally {
 			BusinessObjectFactory.transaction.set(null);
 		}
 	}
 
 	/**
 	 * TODO documentation
 	 * 
 	 * @throws DAOException
 	 */
 	public void rollback() throws DAOException {
 		if (logger.isDebugEnabled()) {
 			logger.debug("rollback() - start");
 		}
 		Transaction transaction = (Transaction)BusinessObjectFactory.transaction.get();
 		try {
 			transaction.rollback();
 		} catch (HibernateException he) {
 			logger.debug("rollback() - error", he);
 			throw new DAOException("session.error.rollback", he);
 		} catch (NullPointerException npe) {
 			logger.warn("rollback() - transaction never started", npe);
 		} finally {
 			BusinessObjectFactory.transaction.set(null);
 		}
 	}
 
 
 	/**
 	 * TODO documentation
 	 */
 	public class Paginator extends net.smartlab.web.page.Paginator implements Collection {
 
 		/**
 		 * Logger for this class
 		 */
 		private final Log logger = LogFactory.getLog(Paginator.class);
 
 		/**
 		 * References the Hibernate query or criteria passed to the constructor.
 		 * It cannot be null.
 		 */
 		private Object statement;
 
 
 		/**
 		 * Constructs an instance on an Hibernate criteria with an unlimited
 		 * number of items per page and an unlimited number of pages displayed.
 		 * 
 		 * @param criteria the Hibernate criteria whose results must be
 		 *        paginated.
 		 * @throws HibernateException if something wrong occurs accessing the
 		 *         database.
 		 */
 		public Paginator(Criteria criteria) throws HibernateException {
 			this(criteria, Paginator.UNLIMITED_ITEMS, Paginator.UNLIMITED_PAGES);
 		}
 
 		/**
 		 * Constructs an instance on an Hibernate criteria with the specified
 		 * number of elements per page and the specified number of pages
 		 * displayed.
 		 * 
 		 * @param criteria the Hibernate criteria whose results must be
 		 *        paginated.
 		 * @param size the number of elements per page.
 		 * @param pages the number of pages to be displayed for quick
 		 *        navigation.
 		 * @throws HibernateException if something wrong occurs accessing the
 		 *         database.
 		 */
 		public Paginator(Criteria criteria, int size, int pages) throws HibernateException {
 			super(size, pages);
 			this.statement = criteria;
 			ResultTransformer rt = ((CriteriaImpl)criteria).getResultTransformer();
 			List temp = new ArrayList();
 			Iterator orderings = ((CriteriaImpl)criteria).iterateOrderings();
 			while (orderings.hasNext()) {
 				Order ordering = ((CriteriaImpl.OrderEntry)orderings.next()).getOrder();
 				orderings.remove();
 				temp.add(ordering);
 			}
 			criteria.setProjection(Projections.rowCount());
 			this.setCount(((Integer)criteria.uniqueResult()).intValue());
 			criteria.setProjection(null);
 			if (rt == null) {
 				rt = Criteria.ROOT_ENTITY;
 			}
 			criteria.setResultTransformer(rt);
 			orderings = temp.iterator();
 			while (orderings.hasNext()) {
 				criteria.addOrder((Order)orderings.next());
 			}
 			this.setSize(size);
 		}
 
 		/**
 		 * Constructs an instance on an Hibernate query with an unlimited number
 		 * of items per page and an unlimited number of pages displayed.
 		 * 
 		 * @param query the Hibernate query whose results must be paginated.
 		 * @throws DAOException if something wrong occurs accessing the
 		 *         underling data layer.
 		 * @throws HibernateException if something wrong occurs accessing the
 		 *         database.
 		 */
 		public Paginator(Query query) throws DAOException, HibernateException {
 			this(query, Paginator.UNLIMITED_ITEMS, Paginator.UNLIMITED_PAGES);
 		}
 
 		/**
 		 * Constructs an instance on an Hibernate query with the specified
 		 * number of elements per page and the specified number of pages
 		 * displayed. FIXME the computation of rowCount is still slow on long
 		 * lists.
 		 * 
 		 * @param query the Hibernate query whose results must be paginated.
 		 * @param size the number of elements per page.
 		 * @param pages the number of pages to be displayed for quick
 		 *        navigation.
 		 * @throws DAOException if something wrong occurs accessing the
 		 *         underling data layer.
 		 * @throws HibernateException if something wrong occurs accessing the
 		 *         database.
 		 */
 		public Paginator(Query query, int size, int pages) throws DAOException, HibernateException {
 			super(size, pages);
 			this.statement = query;
 			int queryCount = query.count();
 			this.setCount(queryCount);
 			this.setSize(size);
 		}
 
 		/**
 		 * @see net.smartlab.web.page.Paginator#setPage(int)
 		 */
 		public void setPage(int page) {
 			if (logger.isDebugEnabled()) {
 				logger.debug("setPage(page = " + page + ") - start");
 			}
 			if (statement instanceof Criteria) {
 				((Criteria)this.statement).setFirstResult((page - 1) * super.getPageSize());
 			} else {
 				((Query)this.statement).setFirstResult((page - 1) * super.getPageSize());
 			}
 			super.setPage(page);
 		}
 
 		/**
 		 * TODO documentation
 		 * 
 		 * @param size
 		 */
 		public void setSize(int size) {
 			if (logger.isDebugEnabled()) {
 				logger.debug("setSize(size = " + size + ") - start");
 			}
 			if (size != UNLIMITED_ITEMS) {
 				super.setPageSize(size);
 				if (statement instanceof Criteria) {
 					((Criteria)this.statement).setMaxResults(size);
 				} else {
 					((Query)this.statement).setMaxResults(size);
 				}
 			} else {
 				super.setPageSize(this.getCount());
 			}
 		}
 
 		/**
 		 * @see net.smartlab.web.page.Paginator#setArray()
 		 */
 		protected void setArray() {
 			if (logger.isDebugEnabled()) {
 				logger.debug("setArray() - start");
 			}
 			try {
 				Iterator elements = null;
 				if (statement instanceof Criteria) {
 					elements = ((Criteria)this.statement).list().iterator();
 				} else {
 					elements = ((Query)this.statement).list().iterator();
 				}
 				for (int i = 0; i < array.length && elements.hasNext(); i++) {
 					array[i] = elements.next();
 				}
 			} catch (HibernateException he) {
 				logger.error("setArray() - error", he);
 			}
 		}
 
 		/**
 		 * @see java.util.Collection#add(java.lang.Object)
 		 */
 		public boolean add(Object obj) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#addAll(java.util.Collection)
 		 */
 		public boolean addAll(Collection collection) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#clear()
 		 */
 		public void clear() {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#contains(java.lang.Object)
 		 */
 		public boolean contains(Object item) {
 			if (logger.isDebugEnabled()) {
 				logger.debug("contains(item = " + item + ") - start");
 			}
 			for (int i = 0; i < array.length; i++) {
 				if (array[i].equals(item)) {
 					return true;
 				}
 			}
 			return false;
 		}
 
 		/**
 		 * @see java.util.Collection#containsAll(java.util.Collection)
 		 */
 		public boolean containsAll(Collection item) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#isEmpty()
 		 */
 		public boolean isEmpty() {
 			return super.getCount() == 0;
 		}
 
 		/**
 		 * @see java.util.Collection#iterator()
 		 */
 		public Iterator iterator() {
 			return this;
 		}
 
 		/**
 		 * @see java.util.Collection#remove(java.lang.Object)
 		 */
 		public boolean remove(Object obj) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#removeAll(java.util.Collection)
 		 */
 		public boolean removeAll(Collection collection) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#retainAll(java.util.Collection)
 		 */
 		public boolean retainAll(Collection collection) {
 			throw new UnsupportedOperationException();
 		}
 
 		/**
 		 * @see java.util.Collection#size()
 		 */
 		public int size() {
 			return super.getCount();
 		}
 
 		/**
 		 * @see java.util.Collection#toArray()
 		 */
 		public Object[] toArray() {
 			return array;
 		}
 
 		/**
 		 * @see java.util.Collection#toArray(java.lang.Object[])
 		 */
 		public Object[] toArray(Object[] array) {
 			return this.array;
 		}
 	}
 }